Table of Contents
Are VFDs efficient?
A VFD is very efficient. Typical efficiencies of 97\% or more are available at full load. At reduced loads the efficiency drops. Typically, VFDs over 10 HP have over 90\% efficiency for loads greater than 25\% of full load.
Does VFD consume power?
With a VFD, the output of the system (air supply in this case) is controlled by directly changing the speed or torque of the motor. At low demand the motor runs slowly and the power consumption decreases in proportion to the demand resulting in increased efficiency and energy savings.
Why do we use VFDs?
VFD stands for Variable Frequency Drive. They are used for controlling the speed of an AC motor. They are also used for ramping up a motor for a smooth startup, or to prevent a heavy load from straining the motor on startup. VFDs allow the operator to control the flow of the pump manually or automatically with a PLC.
Can a VFD replace a softstart?
The good news is that if an existing application has a soft starter in place and speed control is later determined to be a requirement, a VFD can easily replace a soft starter. The opposite is true as well, a soft starter can replace a VFD.
Can VFD increase torque?
Since a VFD cannot increase the voltage above its supply voltage, the current decreases as frequency increases, decreasing the available torque. Theoretically, torque is reduced by the ratio of the base speed to the higher speed (60 hertz / 90 hertz = 67 percent).
Do I need a soft starter?
Soft starters are often the more economical choice for applications that require speed and torque control only during motor startup. Additionally, they are often the ideal solution for applications where space is a concern, as they usually take up less space than variable frequency drives.
Why we are using soft starter?
Soft starters are seen in electrical R/C helicopters, and allow the rotor blades to spool-up in a smooth, controlled manner rather than a sudden surge. In all systems, a soft start limits the inrush current and so improves stability of the power supply and reduces transient voltage drops that may affect other loads.